“Heaven is for Real,” which was written by Todd Burpo with Lynn Vincent, chronicles Burpo’s story of his son Colton. Colton tells his family he visited heaven while he was in emergency surgery for his appendix. The book was first released in 2010 and is still number 12 on the New York Times paperback nonfiction bestseller list for the week of Nov. 24.

“Secretariat” director Randall Wallace is helming the adaptation. The film is set to come to theaters on April 16.

The trailer shows the Burpos waiting as Colton is in surgery and Colton telling his parents of his experiences afterward, including seeing a sister who died in a miscarriage (an incident the Burpos say they had never discussed with Colton) and seeing his great-grandfather.